I’m trying to build a repository with product class as entity. There seems to be something wrong with the Id generator.
Here’s my product entity
Product.java
package com.example.repository.model;
import org.hibernate.annotations.GenericGenerator;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
@Entity
public class Product {
@Id
@GeneratedValue(strategy = GenerationType.AUTO, generator = "system-uuid")
@GenericGenerator(name = "system-uuid", strategy = "uuid2")
private Integer Id;
private String name;
private String type;
private String description;
private Double price;
public Integer getId() {
return Id;
}
public void setId(Integer id) {
Id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public Double getPrice() {
return price;
}
public void setPrice(Double price) {
this.price = price;
}
}
Here’s my application.properties
Application.properties
spring.datasource.url=jdbc:h2:~/Products
spring.datasource.username=sa
spring.datasource.password=
spring.datasource.driver-class-name=org.h2.Driver
spring.h2.console.path=/h2
spring.h2.console.enabled=true
spring.jpa.hibernate.ddl-auto = update
spring.jpa.show-sql=true
And here’s the stack trace
2022-04-20 14:34:55.369 INFO 47972 --- [ main] o.hibernate.annotations.common.Version : HCANN000001: Hibernate Commons Annotations {5.1.2.Final}
2022-04-20 14:34:55.472 INFO 47972 --- [ main] org.hibernate.dialect.Dialect : HHH000400: Using dialect: org.hibernate.dialect.H2Dialect
2022-04-20 14:34:55.689 ERROR 47972 --- [ main] j.LocalContainerEntityManagerFactoryBean : Failed to initialize JPA EntityManagerFactory: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Could not instantiate id generator [entity-name=com.example.repository.model.Product]
2022-04-20 14:34:55.690 WARN 47972 --- [ main] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Could not instantiate id generator [entity-name=com.example.repository.model.Product]
2022-04-20 14:34:55.690 INFO 47972 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Shutdown initiated...
2022-04-20 14:34:55.758 INFO 47972 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Shutdown completed.
2022-04-20 14:34:55.769 INFO 47972 --- [ main] o.apache.catalina.core.StandardService : Stopping service [Tomcat]
2022-04-20 14:34:55.808 INFO 47972 --- [ main] ConditionEvaluationReportLoggingListener :
Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2022-04-20 14:34:55.843 ERROR 47972 --- [ main] o.s.boot.SpringApplication : Application run failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Could not instantiate id generator [entity-name=com.example.repository.model.Product]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1804) ~[spring-beans-5.3.18.jar:5.3.18]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:620) ~[spring-beans-5.3.18.jar:5.3.18]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:542) ~[spring-beans-5.3.18.jar:5.3.18]
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335) ~[spring-beans-5.3.18.jar:5.3.18]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-5.3.18.jar:5.3.18]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333) ~[spring-beans-5.3.18.jar:5.3.18]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.18.jar:5.3.18]
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1154) ~[spring-context-5.3.18.jar:5.3.18]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:908) ~[spring-context-5.3.18.jar:5.3.18]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583) ~[spring-context-5.3.18.jar:5.3.18]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.6.jar:2.6.6]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:740) ~[spring-boot-2.6.6.jar:2.6.6]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:415) ~[spring-boot-2.6.6.jar:2.6.6]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) ~[spring-boot-2.6.6.jar:2.6.6]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1312) ~[spring-boot-2.6.6.jar:2.6.6]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1301) ~[spring-boot-2.6.6.jar:2.6.6]
at com.example.repository.RepositoryApplication.main(RepositoryApplication.java:10) ~[classes/:na]
Caused by: javax.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.MappingException: Could not instantiate id generator [entity-name=com.example.repository.model.Product]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:421) ~[spring-orm-5.3.18.jar:5.3.18]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:396) ~[spring-orm-5.3.18.jar:5.3.18]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) ~[spring-orm-5.3.18.jar:5.3.18]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1863) ~[spring-beans-5.3.18.jar:5.3.18]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1800) ~[spring-beans-5.3.18.jar:5.3.18]
... 16 common frames omitted
Caused by: org.hibernate.MappingException: Could not instantiate id generator [entity-name=com.example.repository.model.Product]
at org.hibernate.id.factory.internal.DefaultIdentifierGeneratorFactory.createIdentifierGenerator(DefaultIdentifierGeneratorFactory.java:147) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
at org.hibernate.mapping.SimpleValue.createIdentifierGenerator(SimpleValue.java:359) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
at org.hibernate.mapping.SimpleValue.createIdentifierGenerator(SimpleValue.java:280) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
at org.hibernate.internal.SessionFactoryImpl.lambda$new$1(SessionFactoryImpl.java:306) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183) ~[na:na]
at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177) ~[na:na]
at java.base/java.util.HashMap$ValueSpliterator.forEachRemaining(HashMap.java:1675) ~[na:na]
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484) ~[na:na]
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474) ~[na:na]
at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150) ~[na:na]
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173) ~[na:na]
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[na:na]
at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497) ~[na:na]
at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:305) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:471) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1498) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:58) ~[spring-orm-5.3.18.jar:5.3.18]
at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.3.18.jar:5.3.18]
at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:409) ~[spring-orm-5.3.18.jar:5.3.18]
... 20 common frames omitted
Caused by: org.hibernate.HibernateException: Unanticipated return type [java.lang.Integer] for UUID conversion
at org.hibernate.id.UUIDGenerator.configure(UUIDGenerator.java:96) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
at org.hibernate.id.factory.internal.DefaultIdentifierGeneratorFactory.createIdentifierGenerator(DefaultIdentifierGeneratorFactory.java:142) ~[hibernate-core-5.6.7.Final.jar:5.6.7.Final]
... 38 common frames omitted
I’m totally new to spring and hibernate and have no idea how to solve this issue.
Thanks in advance.
>Solution :
Exception states:
Caused by: org.hibernate.HibernateException: Unanticipated return type [java.lang.Integer] for UUID conversion
Change id type to String. Integer is not supported for UUID generator:
@Id
@GeneratedValue(strategy = GenerationType.AUTO, generator = "system-uuid")
@GenericGenerator(name = "system-uuid", strategy = "uuid2")
private String id;